The entire FLCL soundtrack is great. DtB had a solid score by Yoko Kanno (wish she could have provided the same for Gemini, but that's still a pretty good OST). Guilty Crown's music is about the only thing the anime has going for it, other than the artwork.

And, as a cinematic masterpiece, the music used in Giant Robo just builds upon everything else that is great about the OVA.

Runners up would be: FLCL,Ergo Proxy,Eureka Seven,Bubblegum Crisis, Princess Mononoke,Cowboy Bebop,Kids On The Slope and One Piece

Oh, Original or 2040?

Original all the way. The soundtrack to that was killer. 2040 was better from a technical stand point but the modern soundtrack didn't have the same charm as the 80's inspired soundtrack that the original had.

The original is also pretty nostalgic to me. It's the first anime i can ever remember where they dubbed the entire soundtrack of insert songs and opening/endings into English and made an effort to make them sound like the original. They gave it a good effort which was rare back then. Dubs were either really horrible or just horrible XD.

The entire FLCL soundtrack is great. DtB had a solid score by Yoko Kanno (wish she could have provided the same for Gemini, but that's still a pretty good OST). Guilty Crown's music is about the only thing the anime has going for it, other than the artwork.

And, as a cinematic masterpiece, the music used in Giant Robo just builds upon everything else that is great about the OVA.

Guess I was just naming my favorite tracks from their OST that I liked already (that, and I was half asleep when I done this ) I pretty much automatically love any of Yoko Kanno and Yuki Kajiura OST. I personally find Gankutsuou soundtrack to be underrated. I can the say same thing for Sword Art Online in terms of music and artwork.